The switches used for switching electrical loads may be transistors, which have an actuation connection and a load path. In an application of this kind, the load path of the transistor is connected in series with the load between terminals for a supply voltage. The transistor is turned on to turn on the load or the transistor is turned off to turn off the load by using an actuation signal which is supplied to the actuation connection of the transistor.
When a transistor of this kind used as a switch is off, the load current flowing through the transistor is zero and the load path has a reverse voltage across it which is high in comparison with the load path voltage when the transistor is on. When the transistor is turned on, the load path voltage falls to a lower value and the load current rises. This load current is definitively dependent on the applied supply voltage and the load.
A critical factor for switching processes, i.e. when the transistor changes from the on state to the off state or when the transistor changes from the off state to the on state, may be steep voltage edges—i.e. large changes in the voltage over time—or steep current edges—i.e. large changes in the current over time. Thus, steep current edges may result, by way of example, in unwanted voltage spikes on parasitic inductances which are formed by supply lines, for example. Steep voltage edges interacting with parasitic resonant circuits may result in unwanted voltage spikes. By way of example, parasitic resonant circuits of this kind include inductances in supply lines and the capacitance of a printed circuit board on which the transistor and the load are mounted.